Radioisotopes emit some extraordinary types of energy
in form of rays (alpha, beta and gamma), which are very helpful to human
beings in minute quantity. These rays are invisible spontaneous and
penetrating. Their presence can be easily detected with the help of the
latest devices such as Geiger Muller and Scintillation Counters. These
instruments are used for the detection of even, the very tiny or minute
quantity of radioactive element present. Thus, new tiny tool
radioactivity is proving very helpful in several fields of daily uses
such as medicine, agriculture and industry. Today, these new tools
unlocking the secrets of many human well beings problems which could
never have been possible by conventional means. Many scientific
researches are being conducted all over the world putting radioisotopes
into use with successful scientific achievements. This article deals
specially with the use of radioisotopes and radiations in the field of
agriculture.

Presently, the radioisotopes are being widely used in
the field of agriculture than in any other field of science and their
application is leading us to the solution of many agriculture problems
in a shorter time and more precisely. Thus, radioisotopes have become a
very important aid to scientists dealing with the solution of
agricultural problems. In addition to this, radioactive tracers and
radiation sources have become indispensable to all the intricate
agricultural research problems. Radioisotopes and radiations give us the
chance to clear the events that once were mysterious in the nutrition
and growth of plants and evolution of new crop varieties. They help us
to clear the casual factors, which produce ill-effects to the plants in
different ways.

In agriculture, radioisotopes are used in the
nutritional studies of major and minor elements, milk production,
mechanism of photosynthesis studies. Plant protection, plant pathology,
action of insecticides, uptake of fertilizers, ions mobility in soil,
and plants and food preservation. In order to determine the correct
nutrition for a plant we need to know the exact soil plant relationship
and the factors involved therein.

Application of radioisotopes and radiation sources in
agricultural research has especially the following advantages:

i)

With the
help of radioisotopes we can easily locate the presence of a single atom
and molecule and their movement. Hence, they give research workers the
opportunity to follow up step by step all kinds of processes that are
related to the nutrition of plant from germination to maturity.

ii)

Very small
quantities of labeled nutrients can be accurately measured in presence
of large quantities of other nutrients.

iii)

The
location of materials can be identified by radio-autography.

iv)

Tracer
technique enables one in tracing those elements taken by the plants
accurately and precisely.

v)

It also
helps to study accurately the effect of one element upon the absorption
of another and their interaction by plants and now it has become very
easy to study properly the phenomenon of interaction among the mineral
nutrients.

The production of radioisotopes by nuclear reactors
and other atomic installations have increased the use of radioisotopes
in the field of agriculture. To obtain an increased yield from the soils
by applying fertilizers, one has got to determine the fertility status
of the soil, which appears to be unproductive. Radioactive phosphorus is
used in most of the investigations that are carried out to determine the
P-status of the soils. Several problems can be solved by this study such
as comparison of various fertilizers, influence of particle size,
placement, time of application, doses, absorption by plants and the
reaction of the applied fertilizer in the soil.

By using radioactive phosphorus research workers have
succeeded to distinguish between soil phosphorus and the fertilizer
phosphorus, taken by the plants. Radioisotopes like Fe, Mn, K, Ca, N, Rb,
C, Cs, Si and Sr etc. and other macro and micro-elements have also been
used by workers in order to find out their movement in different types
of soils and also their position in different clay fractions of the
soils. The radioisotope method is very reliable and helpful in
determining fertility level of soil. Thus, the application of
radioactive elements in agriculture has received tremendous importance
in interpreting certain aspects of soil fertility and other intricate
problems. Radioisotopes have also helped the investigation of the effect
of such factors as cultivation, irrigation methods and time on the root
system of plants.

Recent studies with radioisotopes have also shown
that with many crops, supply of plant nutrients through the leaves is
more quick and effective than the application in soil. For example, it
has been found that a nutrient, which is hardly absorbed upto 10% by
root, can be absorbed upto 90% when applied on leaves. Experimentally,
it has been found that the absorption of nutrients by leaves takes place
not only during the day time but also at night time. Through isotope
technique it is possible not only to determine the amount of nutrient
that are taken by plants, but it also gives the opportunity to know
about their movement and their places of accumulation. In the plants,
mostly radiophosphorus has been used for this kind of research works and
the results have shown that absorption speed of this nutrient was more
than the expected.

Radioisotopes and radiation is used in mutation
induction. Mutation is a sudden heritabic changes of the hereditary
factors organs on the chromosomes of the organisms. The employment of
radiation to induce hereditary variants is a useful tool of potential
value in agriculture. We have been able to show conclusively that, with
radiations changes can be brought about in the organization of the
hereditary make up that are useful in plant improvement.

Radioisotopes and ionizing radiations are of
inestimable value for obtaining an insight into ecological habits of
insects. With the aid of radioisotopes we can find out population
density the maturity rate during different stages of the life cycle,
modes of dispersal, movement and migration, flight range hibernating
places, egg living sites relation to predators, parasites, feeding?
mating habits and disease transmission etc.